Post by mlrr on Jul 14, 2016 7:00:21 GMT -5
Hello All,
Over the years I have regularly expressed my dissatisfaction with the max. speed performance of the HHP-8 locomotives and similarly the Acela Express train sets.
One remedy that seemed to work early on was bypassing the factory board from the decoder to the motor directly. This improved things but then I noticed that this only helped the HHPs to max out around 80 MPH.
In recent month, 2/3 of my HHPs would mad out around 60 MPH (this is a big "No No" for NEC operations). I've considered replacing the motors as an option as my experience working the Acela/NEC Layout at the Springfield shows for a number of years, Bachmann motors tend to show signs that they're on their last leg by dropping in max speed but I don't think my trains have run nearly as much as the Acelas on that layout (and at least mine would stop occasionally, lol).
I will say that I have found the cause of the problem and now they max out anywhere from 113 to 118 scale miles per hour.
So what's the culprit?
It turns out that the lucrative Back EMF feature of my TCS T1 decoders is responsible for the lower top speeds. When disabled, there was a huge difference in performance. But the down side is that the HHP-8s does not start smoothly and didn't start moving until speed step 30. The remedy for this was adjusting the dither with CV 56 and CV 57. The online manual walks you through how to adjust the dither so that your locomotive still performs similar to how it would with BEMF enabled. See page 17 for how to adjust the dither. The settings for my HHPs were CV57 = 165 and CV56 = 6. You may also need to adjust your VStart, Vmid and Vmax.
Keep in mind that I also removed the capacitors on the circuit board. On the first run of HHP-8s (650, 655 and 664) they are easily noticeable as these yellowish bulbs marked C1 through C4 on pc board. Removing these will not affect the operation of your locomotive and were installed for the purposes of mitigating interference with televisions and cell phones due to international requirements (Bachmann is an international company after all). Sometimes capacitors are mounted directly to the motor (as was found on one of my newer acela power cars). Removing these capacitors does not void the warranty according to their website.
I haven't attempted this with my Acela power cars yet but they have the same decoders and I suspect they are contributing to their performance in the same way.
Thanks for taking the time to read this post. I know I'm not the only one who have had this issue but I also know that there are few people online who can relate and contribute effectively to this issue (i.e. most chiming in don't model high speed passenger trains so you're more likely to get comments about running trains too fast than an actual solution). As you can see, I had a bunch of well-intended suggestions but the solution was never suggested by anyone before.
With all that said, I'm a little less skeptical about the Bachmann Sound Value Amtrak ACS-64 that will be coming out next year knowing that there are actual remedies for this challenge.
Read more: atlasrescueforum.proboards.com/thread/4828/bachmann-speed-performance-issues-solution#ixzz4ENpa3vst
Over the years I have regularly expressed my dissatisfaction with the max. speed performance of the HHP-8 locomotives and similarly the Acela Express train sets.
One remedy that seemed to work early on was bypassing the factory board from the decoder to the motor directly. This improved things but then I noticed that this only helped the HHPs to max out around 80 MPH.
In recent month, 2/3 of my HHPs would mad out around 60 MPH (this is a big "No No" for NEC operations). I've considered replacing the motors as an option as my experience working the Acela/NEC Layout at the Springfield shows for a number of years, Bachmann motors tend to show signs that they're on their last leg by dropping in max speed but I don't think my trains have run nearly as much as the Acelas on that layout (and at least mine would stop occasionally, lol).
I will say that I have found the cause of the problem and now they max out anywhere from 113 to 118 scale miles per hour.
So what's the culprit?
It turns out that the lucrative Back EMF feature of my TCS T1 decoders is responsible for the lower top speeds. When disabled, there was a huge difference in performance. But the down side is that the HHP-8s does not start smoothly and didn't start moving until speed step 30. The remedy for this was adjusting the dither with CV 56 and CV 57. The online manual walks you through how to adjust the dither so that your locomotive still performs similar to how it would with BEMF enabled. See page 17 for how to adjust the dither. The settings for my HHPs were CV57 = 165 and CV56 = 6. You may also need to adjust your VStart, Vmid and Vmax.
Keep in mind that I also removed the capacitors on the circuit board. On the first run of HHP-8s (650, 655 and 664) they are easily noticeable as these yellowish bulbs marked C1 through C4 on pc board. Removing these will not affect the operation of your locomotive and were installed for the purposes of mitigating interference with televisions and cell phones due to international requirements (Bachmann is an international company after all). Sometimes capacitors are mounted directly to the motor (as was found on one of my newer acela power cars). Removing these capacitors does not void the warranty according to their website.
I haven't attempted this with my Acela power cars yet but they have the same decoders and I suspect they are contributing to their performance in the same way.
Thanks for taking the time to read this post. I know I'm not the only one who have had this issue but I also know that there are few people online who can relate and contribute effectively to this issue (i.e. most chiming in don't model high speed passenger trains so you're more likely to get comments about running trains too fast than an actual solution). As you can see, I had a bunch of well-intended suggestions but the solution was never suggested by anyone before.
With all that said, I'm a little less skeptical about the Bachmann Sound Value Amtrak ACS-64 that will be coming out next year knowing that there are actual remedies for this challenge.
Read more: atlasrescueforum.proboards.com/thread/4828/bachmann-speed-performance-issues-solution#ixzz4ENpa3vst
